diff --git a/Documentation/x86/intel_rdt_ui.txt b/Documentation/x86/intel_rdt_ui.txt
index 4d8848e4e224a8eb8207c8fb7469be57340f1671..6851854cf69dd8334d61cd55d2b02bd13b32daeb 100644
--- a/Documentation/x86/intel_rdt_ui.txt
+++ b/Documentation/x86/intel_rdt_ui.txt
@@ -87,6 +87,17 @@ with the following files:
bytes) at which a previously used LLC_occupancy
counter can be considered for re-use.
+Finally, in the top level of the "info" directory there is a file
+named "last_cmd_status". This is reset with every "command" issued
+via the file system (making new directories or writing to any of the
+control files). If the command was successful, it will read as "ok".
+If the command failed, it will provide more information that can be
+conveyed in the error returns from file operations. E.g.
+
+ # echo L3:0=f7 > schemata
+ bash: echo: write error: Invalid argument
+ # cat info/last_cmd_status
+ mask f7 has non-consecutive 1-bits
Resource alloc and monitor groups
---------------------------------
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index cd5fc61ba45020f66bb8e619b4c033eb6b786a63..88dcf8479013569e93a58c278badaf690c29a27b 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -267,6 +267,7 @@ static void rdt_get_cdp_l3_config(int type)
r->num_closid = r_l3->num_closid / 2;
r->cache.cbm_len = r_l3->cache.cbm_len;
r->default_ctrl = r_l3->default_ctrl;
+ r->cache.shareable_bits = r_l3->cache.shareable_bits;
r->data_width = (r->cache.cbm_len + 3) / 4;
r->alloc_capable = true;
/*
diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index a43a72d8e88e45ef76a2dee5e5a4abbd0ecab308..3397244984f559ec405ab82b242b82ad5ee49c7f 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -127,12 +127,15 @@ struct rdtgroup {
#define RFTYPE_BASE BIT(1)
#define RF_CTRLSHIFT 4
#define RF_MONSHIFT 5
+#define RF_TOPSHIFT 6
#define RFTYPE_CTRL BIT(RF_CTRLSHIFT)
#define RFTYPE_MON BIT(RF_MONSHIFT)
+#define RFTYPE_TOP BIT(RF_TOPSHIFT)
#define RFTYPE_RES_CACHE BIT(8)
#define RFTYPE_RES_MB BIT(9)
#define RF_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
#define RF_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
+#define RF_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP)
#define RF_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL)
/* List of all resource groups */
@@ -409,6 +412,10 @@ union cpuid_0x10_x_edx {
unsigned int full;
};
+void rdt_last_cmd_clear(void);
+void rdt_last_cmd_puts(const char *s);
+void rdt_last_cmd_printf(const char *fmt, ...);
+
void rdt_ctrl_update(void *arg);
struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);
void rdtgroup_kn_unlock(struct kernfs_node *kn);
diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index f6ea94f8954a7d5e862b4f25a98b963d664007ec..23e1d5c249c60bca179e2ede61a98366e426beec 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -42,15 +42,22 @@ static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
/*
* Only linear delay values is supported for current Intel SKUs.
*/
- if (!r->membw.delay_linear)
+ if (!r->membw.delay_linear) {
+ rdt_last_cmd_puts("No support for non-linear MB domains\n");
return false;
+ }
ret = kstrtoul(buf, 10, &bw);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
return false;
+ }
- if (bw < r->membw.min_bw || bw > r->default_ctrl)
+ if (bw < r->membw.min_bw || bw > r->default_ctrl) {
+ rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
+ r->membw.min_bw, r->default_ctrl);
return false;
+ }
*data = roundup(bw, (unsigned long)r->membw.bw_gran);
return true;
@@ -60,8 +67,10 @@ int parse_bw(char *buf, struct rdt_resource *r, struct rdt_domain *d)
{
unsigned long data;
- if (d->have_new_ctrl)
+ if (d->have_new_ctrl) {
+ rdt_last_cmd_printf("duplicate domain %d\n", d->id);
return -EINVAL;
+ }
if (!bw_validate(buf, &data, r))
return -EINVAL;
@@ -84,20 +93,29 @@ static bool cbm_validate(char *buf, unsigned long *data, struct rdt_resource *r)
int ret;
ret = kstrtoul(buf, 16, &val);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_printf("non-hex character in mask %s\n", buf);
return false;
+ }
- if (val == 0 || val > r->default_ctrl)
+ if (val == 0 || val > r->default_ctrl) {
+ rdt_last_cmd_puts("mask out of range\n");
return false;
+ }
first_bit = find_first_bit(&val, cbm_len);
zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
- if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)
+ if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len) {
+ rdt_last_cmd_printf("mask %lx has non-consecutive 1-bits\n", val);
return false;
+ }
- if ((zero_bit - first_bit) < r->cache.min_cbm_bits)
+ if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
+ rdt_last_cmd_printf("Need at least %d bits in mask\n",
+ r->cache.min_cbm_bits);
return false;
+ }
*data = val;
return true;
@@ -111,8 +129,10 @@ int parse_cbm(char *buf, struct rdt_resource *r, struct rdt_domain *d)
{
unsigned long data;
- if (d->have_new_ctrl)
+ if (d->have_new_ctrl) {
+ rdt_last_cmd_printf("duplicate domain %d\n", d->id);
return -EINVAL;
+ }
if(!cbm_validate(buf, &data, r))
return -EINVAL;
@@ -139,8 +159,10 @@ static int parse_line(char *line, struct rdt_resource *r)
return 0;
dom = strsep(&line, ";");
id = strsep(&dom, "=");
- if (!dom || kstrtoul(id, 10, &dom_id))
+ if (!dom || kstrtoul(id, 10, &dom_id)) {
+ rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
return -EINVAL;
+ }
dom = strim(dom);
list_for_each_entry(d, &r->domains, list) {
if (d->id == dom_id) {
@@ -196,6 +218,7 @@ static int rdtgroup_parse_resource(char *resname, char *tok, int closid)
if (!strcmp(resname, r->name) && closid < r->num_closid)
return parse_line(tok, r);
}
+ rdt_last_cmd_printf("unknown/unsupported resource name '%s'\n", resname);
return -EINVAL;
}
@@ -218,6 +241,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
rdtgroup_kn_unlock(of->kn);
return -ENOENT;
}
+ rdt_last_cmd_clear();
closid = rdtgrp->closid;
@@ -229,6 +253,12 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
while ((tok = strsep(&buf, "\n")) != NULL) {
resname = strim(strsep(&tok, ":"));
if (!tok) {
+ rdt_last_cmd_puts("Missing ':'\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (tok[0] == '\0') {
+ rdt_last_cmd_printf("Missing '%s' value\n", resname);
ret = -EINVAL;
goto out;
}
diff --git a/arch/x86/kernel/cpu/intel_rdt_monitor.c b/arch/x86/kernel/cpu/intel_rdt_monitor.c
index 30827510094befb37aec9be1b356201a3644dd5e..681450eee428b8b07f9fb3a3b1fd5551a5c18cec 100644
--- a/arch/x86/kernel/cpu/intel_rdt_monitor.c
+++ b/arch/x86/kernel/cpu/intel_rdt_monitor.c
@@ -51,7 +51,7 @@ static LIST_HEAD(rmid_free_lru);
* may have a occupancy value > intel_cqm_threshold. User can change
* the threshold occupancy value.
*/
-unsigned int rmid_limbo_count;
+static unsigned int rmid_limbo_count;
/**
* @rmid_entry - The entry in the limbo and free lists.
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index a869d4a073c5ced61e19977eccaa94cf8891e208..64c5ff97ee0d76c98e2e76869ddc30475a602599 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -24,6 +24,7 @@
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/kernfs.h>
+#include <linux/seq_buf.h>
#include <linux/seq_file.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
@@ -51,6 +52,31 @@ static struct kernfs_node *kn_mongrp;
/* Kernel fs node for "mon_data" directory under root */
static struct kernfs_node *kn_mondata;
+static struct seq_buf last_cmd_status;
+static char last_cmd_status_buf[512];
+
+void rdt_last_cmd_clear(void)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+ seq_buf_clear(&last_cmd_status);
+}
+
+void rdt_last_cmd_puts(const char *s)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+ seq_buf_puts(&last_cmd_status, s);
+}
+
+void rdt_last_cmd_printf(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ lockdep_assert_held(&rdtgroup_mutex);
+ seq_buf_vprintf(&last_cmd_status, fmt, ap);
+ va_end(ap);
+}
+
/*
* Trivial allocator for CLOSIDs. Since h/w only supports a small number,
* we can keep a bitmap of free CLOSIDs in a single integer.
@@ -238,8 +264,10 @@ static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
/* Check whether cpus belong to parent ctrl group */
cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
- if (cpumask_weight(tmpmask))
+ if (cpumask_weight(tmpmask)) {
+ rdt_last_cmd_puts("can only add CPUs to mongroup that belong to parent\n");
return -EINVAL;
+ }
/* Check whether cpus are dropped from this group */
cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
@@ -291,8 +319,10 @@ static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
if (cpumask_weight(tmpmask)) {
/* Can't drop from default group */
- if (rdtgrp == &rdtgroup_default)
+ if (rdtgrp == &rdtgroup_default) {
+ rdt_last_cmd_puts("Can't drop CPUs from default group\n");
return -EINVAL;
+ }
/* Give any dropped cpus to rdtgroup_default */
cpumask_or(&rdtgroup_default.cpu_mask,
@@ -357,8 +387,10 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
}
rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ rdt_last_cmd_clear();
if (!rdtgrp) {
ret = -ENOENT;
+ rdt_last_cmd_puts("directory was removed\n");
goto unlock;
}
@@ -367,13 +399,16 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
else
ret = cpumask_parse(buf, newmask);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_puts("bad cpu list/mask\n");
goto unlock;
+ }
/* check that user didn't specify any offline cpus */
cpumask_andnot(tmpmask, newmask, cpu_online_mask);
if (cpumask_weight(tmpmask)) {
ret = -EINVAL;
+ rdt_last_cmd_puts("can only assign online cpus\n");
goto unlock;
}
@@ -452,6 +487,7 @@ static int __rdtgroup_move_task(struct task_struct *tsk,
*/
atomic_dec(&rdtgrp->waitcount);
kfree(callback);
+ rdt_last_cmd_puts("task exited\n");
} else {
/*
* For ctrl_mon groups move both closid and rmid.
@@ -462,10 +498,12 @@ static int __rdtgroup_move_task(struct task_struct *tsk,
tsk->closid = rdtgrp->closid;
tsk->rmid = rdtgrp->mon.rmid;
} else if (rdtgrp->type == RDTMON_GROUP) {
- if (rdtgrp->mon.parent->closid == tsk->closid)
+ if (rdtgrp->mon.parent->closid == tsk->closid) {
tsk->rmid = rdtgrp->mon.rmid;
- else
+ } else {
+ rdt_last_cmd_puts("Can't move task to different control group\n");
ret = -EINVAL;
+ }
}
}
return ret;
@@ -484,8 +522,10 @@ static int rdtgroup_task_write_permission(struct task_struct *task,
*/
if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
!uid_eq(cred->euid, tcred->uid) &&
- !uid_eq(cred->euid, tcred->suid))
+ !uid_eq(cred->euid, tcred->suid)) {
+ rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
ret = -EPERM;
+ }
put_cred(tcred);
return ret;
@@ -502,6 +542,7 @@ static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
tsk = find_task_by_vpid(pid);
if (!tsk) {
rcu_read_unlock();
+ rdt_last_cmd_printf("No task %d\n", pid);
return -ESRCH;
}
} else {
@@ -529,6 +570,7 @@ static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
return -EINVAL;
rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ rdt_last_cmd_clear();
if (rdtgrp)
ret = rdtgroup_move_task(pid, rdtgrp, of);
@@ -569,6 +611,21 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of,
return ret;
}
+static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ int len;
+
+ mutex_lock(&rdtgroup_mutex);
+ len = seq_buf_used(&last_cmd_status);
+ if (len)
+ seq_printf(seq, "%.*s", len, last_cmd_status_buf);
+ else
+ seq_puts(seq, "ok\n");
+ mutex_unlock(&rdtgroup_mutex);
+ return 0;
+}
+
static int rdt_num_closids_show(struct kernfs_open_file *of,
struct seq_file *seq, void *v)
{
@@ -685,6 +742,13 @@ static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
/* rdtgroup information files for one cache resource. */
static struct rftype res_common_files[] = {
+ {
+ .name = "last_cmd_status",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_last_cmd_status_show,
+ .fflags = RF_TOP_INFO,
+ },
{
.name = "num_closids",
.mode = 0444,
@@ -855,6 +919,10 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
return PTR_ERR(kn_info);
kernfs_get(kn_info);
+ ret = rdtgroup_add_files(kn_info, RF_TOP_INFO);
+ if (ret)
+ goto out_destroy;
+
for_each_alloc_enabled_rdt_resource(r) {
fflags = r->fflags | RF_CTRL_INFO;
ret = rdtgroup_mkdir_info_resdir(r, r->name, fflags);
@@ -1081,6 +1149,7 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
struct dentry *dentry;
int ret;
+ cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
/*
* resctrl file system can only be mounted once.
@@ -1130,12 +1199,12 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
goto out_mondata;
if (rdt_alloc_capable)
- static_branch_enable(&rdt_alloc_enable_key);
+ static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
if (rdt_mon_capable)
- static_branch_enable(&rdt_mon_enable_key);
+ static_branch_enable_cpuslocked(&rdt_mon_enable_key);
if (rdt_alloc_capable || rdt_mon_capable)
- static_branch_enable(&rdt_enable_key);
+ static_branch_enable_cpuslocked(&rdt_enable_key);
if (is_mbm_enabled()) {
r = &rdt_resources_all[RDT_RESOURCE_L3];
@@ -1156,7 +1225,9 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
out_cdp:
cdp_disable();
out:
+ rdt_last_cmd_clear();
mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
return dentry;
}
@@ -1295,9 +1366,7 @@ static void rmdir_all_sub(void)
kfree(rdtgrp);
}
/* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
- get_online_cpus();
update_closid_rmid(cpu_online_mask, &rdtgroup_default);
- put_online_cpus();
kernfs_remove(kn_info);
kernfs_remove(kn_mongrp);
@@ -1308,6 +1377,7 @@ static void rdt_kill_sb(struct super_block *sb)
{
struct rdt_resource *r;
+ cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
/*Put everything back to default values. */
@@ -1315,11 +1385,12 @@ static void rdt_kill_sb(struct super_block *sb)
reset_all_ctrls(r);
cdp_disable();
rmdir_all_sub();
- static_branch_disable(&rdt_alloc_enable_key);
- static_branch_disable(&rdt_mon_enable_key);
- static_branch_disable(&rdt_enable_key);
+ static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
+ static_branch_disable_cpuslocked(&rdt_mon_enable_key);
+ static_branch_disable_cpuslocked(&rdt_enable_key);
kernfs_kill_sb(sb);
mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
}
static struct file_system_type rdt_fs_type = {
@@ -1524,8 +1595,10 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
int ret;
prdtgrp = rdtgroup_kn_lock_live(prgrp_kn);
+ rdt_last_cmd_clear();
if (!prdtgrp) {
ret = -ENODEV;
+ rdt_last_cmd_puts("directory was removed\n");
goto out_unlock;
}
@@ -1533,6 +1606,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
if (!rdtgrp) {
ret = -ENOSPC;
+ rdt_last_cmd_puts("kernel out of memory\n");
goto out_unlock;
}
*r = rdtgrp;
@@ -1544,6 +1618,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
if (IS_ERR(kn)) {
ret = PTR_ERR(kn);
+ rdt_last_cmd_puts("kernfs create error\n");
goto out_free_rgrp;
}
rdtgrp->kn = kn;
@@ -1557,24 +1632,31 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
kernfs_get(kn);
ret = rdtgroup_kn_set_ugid(kn);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_puts("kernfs perm error\n");
goto out_destroy;
+ }
- files = RFTYPE_BASE | RFTYPE_CTRL;
files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
ret = rdtgroup_add_files(kn, files);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_puts("kernfs fill error\n");
goto out_destroy;
+ }
if (rdt_mon_capable) {
ret = alloc_rmid();
- if (ret < 0)
+ if (ret < 0) {
+ rdt_last_cmd_puts("out of RMIDs\n");
goto out_destroy;
+ }
rdtgrp->mon.rmid = ret;
ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
goto out_idfree;
+ }
}
kernfs_activate(kn);
@@ -1652,8 +1734,10 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
kn = rdtgrp->kn;
ret = closid_alloc();
- if (ret < 0)
+ if (ret < 0) {
+ rdt_last_cmd_puts("out of CLOSIDs\n");
goto out_common_fail;
+ }
closid = ret;
rdtgrp->closid = closid;
@@ -1665,8 +1749,10 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
* of tasks and cpus to monitor.
*/
ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
- if (ret)
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
goto out_id_free;
+ }
}
goto out_unlock;
@@ -1902,6 +1988,9 @@ int __init rdtgroup_init(void)
{
int ret = 0;
+ seq_buf_init(&last_cmd_status, last_cmd_status_buf,
+ sizeof(last_cmd_status_buf));
+
ret = rdtgroup_setup_root();
if (ret)
return ret;